gdb/

gdb/
	* exceptions.h (enum errors): New entry TARGET_CLOSE_ERROR.
	* remote.c (trace_error): Remove the special handling of '2'.
	(readchar) <SERIAL_EOF>
	(readchar) <SERIAL_ERROR>
	(getpkt_or_notif_sane_1): Use TARGET_CLOSE_ERROR for them.
	(remote_get_trace_status): Call throw_exception if EX is
	TARGET_CLOSE_ERROR.
	* utils.c (perror_with_name): Rename to ...
	(throw_perror_with_name): ... here.  New parameter errcode, describe it
	in the function comment.
	(perror_with_name): New function wrapper.
	* utils.h (enum errors): New stub declaration.
	(throw_perror_with_name): New declaration.

gdb/testsuite/
	* gdb.server/server-kill.c: New file.
	* gdb.server/server-kill.exp: New file.